Commit Graph

4 Commits

Author SHA1 Message Date
Paul Eggert
581c785bf3 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.

I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah.  I don't
know why I run into these diagnostics whereas others evidently do not.

remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
2022-01-01 11:40:24 -08:00
Noah Goldstein
cca457f9c5 x86: Optimize L(less_vec) case in memcmpeq-evex.S
No bug.
Optimizations are twofold.

1) Replace page cross and 0/1 checks with masked load instructions in
   L(less_vec). In applications this reduces branch-misses in the
   hot [0, 32] case.
2) Change controlflow so that L(less_vec) case gets the fall through.

Change 2) helps copies in the [0, 32] size range but comes at the cost
of copies in the [33, 64] size range.  From profiles of GCC and
Python3, 94%+ and 99%+ of calls are in the [0, 32] range so this
appears to the the right tradeoff.

Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2021-12-27 03:18:58 -06:00
Noah Goldstein
9b7cfab180 x86_64: Add evex optimized __memcmpeq in memcmpeq-evex.S
No bug. This commit adds new optimized __memcmpeq implementation for
evex.

The primary optimizations are:

1) skipping the logic to find the difference of the first mismatched
byte.

2) not updating src/dst addresses as the non-equals logic does not
need to be reused by different areas.
2021-10-27 13:03:46 -05:00
Noah Goldstein
cf4fd28ea4 x86_64: Add support for __memcmpeq using sse2, avx2, and evex
No bug. This commit adds support for __memcmpeq to be implemented
seperately from memcmp. Support is added for versions optimized with
sse2, avx2, and evex.
2021-10-27 13:03:46 -05:00